An issue that occurred recently for a number of WP users was that suddenly links, inlcuding menu links, to their Blog page resulted in an Error 404 page. The thread is here.

I, like some others, thought it to be connected to the recent WP upgrade. Maybe it is indirectly but I tired of waiting so started a program of plugin dactivations this morning. The very first one being WP Super Cache, resolved the issue.

I have suggested in the thread above that other users report back on whether deactivating WP Super cahe resolved the issue for them so you can get a handle on the extent of the issue.

Are the 404 errors due to link URLs being wrong or due to linked pages not being available? In other words, do the pages being linked to display without errors if you type their URLs in a web browser address bar instead of taking a link from another page?

I don’t have that problem here with any of multiple installations. It might be a Permalink issue. I use a “/%post_id%/%postname%/” custom Permalink structure that likely is different than what you are using. I suggest that you go to Settings/Permalinks and simply click the “Save Changes” button which can fix Permalinks under certain circumstances.

As I had already deactivated WP Super cache I had to activate it again to try your idea. However, in activating it I was presented with all the setup tabs and noted that the settings were considerably different to what I had previously set. (Maybe they are the default settings). I would have thought that deactivating would not affect settings.

Anyway after setting up again, my Blog links still work.

Still going at the end of the day. I’ll leave it there unless it reoccurs.